Arbitrary-precision arithmetic for Swift, in Swift
import BigNum
BigRat.sqrt(2, precision:128) // 240615969168004511545033772477625056927/170141183460469231731687303715884105728
BigFloat.exp(1, precision:128) // 2.718281828459045235360287471352662497759This module offers two flavors of Arbitrary-precision types that conforms to FloatingPoint.
BigRat- Arbitrary-precision rational number.BigFloat- Arbitrary-precision floating point.
In addition to all arithmetic operations that FloatingPoint supports. Most of the functions in <math.h> are offered as static functions. As you see in the synopsis above, all arithmetic functions and operators that are lossy can take precision:Int as an optional argument. When omitted the value of BigRat.precision or BigFloat.precision is used (default:64).
BigFloat.sqrt(2) // 1.41421356237309504876
BigFloat.precision = 128
BigFloat.sqrt(2) // 1.414213562373095048801688724209698078569BigInt, an arbitrary-precision interger type is internally used and re-exported so you don't have to import BigInt just for that. BigInt is also extended with .over() method so instead of constructing BigRat directly, you can:
BigInt(3260954456333195553).over(BigInt(2305843009213693952)) // == BigRat.sqrt(2)$ git clone https://github.com/dankogai/swift-bignum.git
$ cd swift-bignum # the following assumes your $PWD is here
$ swift buildSimply
$ scripts/run-repl.shor
$ swift run --repl
and in your repl,
[0/0] Build complete!
Launching Swift REPL with arguments: -I/Users/dankogai/github/swift-bignum/.build/x86_64-apple-macosx/release -L/Users/dankogai/github/swift-bignum/.build/x86_64-apple-macosx/release -lBigNum__REPL -I/Users/dankogai/github/swift-bignum/.build/checkouts/swift-numerics/Sources/_NumericsShims/include
Welcome to Swift version 5.5.2-dev.
Type :help for assistance.
1> import BigNum
2> var bf = BigFloat.sqrt(2, precision:128)
bf: BigNum.BigFloat = {
scale = -127
mantissa = {
magnitude = {
kind = array
storage = 2 values {
[0] = 6448461645324402335
[1] = 13043817825332782212
}
}
sign = plus
}
}
3> print(bf)
1.414213562373095048801688724209698078569Simply add the package from Package Dependencies tab of the Project.
Enter https://github.com/dankogai/swift-bignum in the search field and click [Add Package]
Now you are able to import BigNum.
Now all you have to do is build and enjoy!
If you enconter errors like Missing required module '_NumericShims', try cleaning up your ~/Library/Developer/Xcode/DerivedData.
Add the following to the dependencies section:
.package(
url: "https://github.com/dankogai/swift-bignum.git", .branch("main")
)and the following to the .target argument:
.target(
name: "YourSwiftyPackage",
dependencies: ["BigNum"])Now all you have to do is:
import BigNumin your code. Enjoy!
Swift 5 or better, OS X or Linux to build.
- Depends on attaswift/BigInt for internal representation of
BigFloatandBigRat. - Depends on apple/swift-numerics since
version 5.1 for the
ElementaryFunctionsprotocol. - Prior versions depended on dankogai/swift-floatingpoint for the
FloatingPointMathprotocols but it is replaced by theElementaryFunctions.